Adding a custom field on checkout form to "Add gift wrap"

I'd like to add a custom field on the checkout page that would be always present - it'd probably be just a checkbox that can be used to add gift wrap to the order. What is the best way to achieve this. I'd had a quick look at adding custom code and css - but I think I'd need to access the commerce API to add it to the order price etc
I've only just started using squarespace so any suggestions would be helpful

You will need to use custom checkout form. I have linked to the support document below. But please note that you won’t be able to charge extra for gift wrapping at the checkout stage, just a tick box as to whether they would like gift wrapping or not.

https://support.squarespace.com/hc/en-us/articles/206540907-Creating-a-custom-checkout-form

Unfortunately you can’t add code or css to the checkout page, it is essentially locked down.

If you would like to charge extra the bulb there are some work arounds in order to get the user to essentially add gift wrapping to their cart before the checkout page. For example you could have a pop up that appears when a user adds an item to their cart which asks if they would like gift wrapping.

How can we add $2 to the total, if gifting option is selected?

Hey @Johnjwood, 

You may want to consider creating a custom checkout form for that. Check this Squarespace help article for more specifics:

Creating a custom checkout form

We created a workaround by adding it to the shipping option.  For example:

• Shipping Option 1: First Class Shipping (£6.50)
• Shipping Option 2: First Class Shipping + Gift Wrapping (£7.50)

It's not particularly elegant but it's working well for us.  Our site is at skywavegin.com

Ive watched the video, but i still dont know, how to add up extra price for wrap ect. anybody help?